Correlation of exit sites of inducible ventricular tachycardia post‐ST elevation myocardial infarction on electrophysiology study, with region of infarct

Abstract

BackgroundVentricular arrhythmia (VA) is the most common cause of sudden cardiac death post‐ST elevation myocardial infarction (STEMI). Ventricular tachycardia (VT) may be inducible in electrophysiology studies (EPS) early (<40 days) post‐STEMI. Whether it originates from the infarct site remains unknown. We examined the correlation between inducible VT and infarct location post‐STEMI.AimsTo investigate the correlation between inducible VT and infarct location post‐STEMI.MethodsWe retrospectively analysed 46 patients from 2005 to 2017 with STEMI who underwent early programmed ventricular stimulation through EPS (>48 h post‐STEMI and <40 days from admission). Gated heart pool scans were used to visualise infarct scar regions, and VT exit sites were derived from induction 12‐lead electrocardiography. Patients were followed up for primary outcomes of recurrent VA and all‐cause mortality.ResultsForty‐six patients were included for analysis, with 50 uniquely induced VT exit sites. Mean left ventricular ejection fraction was 30 ± 8.7% and 22% had impaired right ventricular ejection fraction. Mean time from presentation to EPS was 16 ± 31.3 days. Of the induced VT, 44 (88%) were from within scar and scar‐border regions, whereas 6 (12%) of the induced VT were found to be remote to imaging‐derived scar. Over a median follow‐up period of 75 months, 6 (13%) patients died, and 7 (15%) patients had recurrent VA. No deaths occurred in patients with remote VT.ConclusionThe majority of early inducible post‐infarct VT arises from acute myocardial scar; however, a small portion arises from sites remote from scars with a possible focal aetiology.